ON Semiconductor NIS5431, NIS545, NIS54 User Manual

NIS54xxGEVB
NIS54xx Evaluation

Board User’s Manual

eFuse test board with multiple
subcircuits for evaluation of
overvoltage protection,
overcurrent protection,
controlled slew rate, and

thermal shutdown features

EVAL BOARD USER’S MANUAL

Introduction

Engineers developing a varied array of systems
utilize sophisticated integrated eFuses to serve a
variety of purposes. They may be found connected to

3.3, 5, and 12 V power rails and have many
interesting features.

The primary features of eFuses are:

 Overvoltage clamping

 Adjustable current limiting

 Enable/Fault control

 Thermal shutdown

 Controllable slew rate

Figure 1: The NIS545xGEVB evaluation

board

This evaluation board has many features which
make it simple to observe the functionality and
performance of the new NIS54xx line of eFuses:

 Multiple connectors available for all eFuse

pins (VCC, GND, enable, ILIM, dv/dt)

 Input and output capacitors

 A pushbutton switch and a MOSFET

connect the enable pin to GND or float it as
needed

 Green and yellow LEDs to indicate whether

the eFuse enable pin voltage is high (device
enabled) or low (device disabled)

 Three current limit resistor options available

directly on the board (10, 18, 50 Ω)

 Two load resistor options (5 and 10 Ω) on

the board

 A pushbutton switch to short circuit the

load, featuring an indicator LED which is on
when the output voltage is high during
normal operation

 An easy means of connecting an external

copper heat sink for thermal evaluation

 Kelvin or direct sensing options via the

jumper between pin 1 and 2 for the NIS54xx

© Semiconductor Components Industries, LLC, 2015

April, 2015 − Rev. 2

NIS54xxGEVB

Figure 2: Schematic for the evaluation board.

The user’s manual is divided into two sections. The first section is for the NIS5431 3.3 V series of devices.

The second section covers the NIS545x 5 V series of devices. For these devices ensure that J1 is in the “54xx”
position.

Figure 3: Features of the evaluation board.

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NIS54xxGEVB

NIS5431 Overvoltage Protection

Connect the eFuse to a variable DC power supply. Place jumpers J2 (10 Ω), J1 (5431), J4, J8, and J13.
Turn the power supply from 3.3 to 10 V to observe the overvoltage protection circuit in operation. The input
voltage will rise, but the output voltage will be maintained at the Vclamp level of about 3.8 V. After conducting 1.1
A with a voltage drop of 6.2 V, the device will reach its thermal shutdown point and latch off. The green indicator
LEDs will turn off and the yellow “fault” indicator LED will be on. An auto-retry eFuse (MT2 part number suffix)
does not latch and automatically cycles the enable pin. For auto-retry eFuses the demo board’s green and yellow
indicator enable pin indicator LEDs will flash as the enable pin cycles between states.

Figure 4: In this test, the input voltage (blue trace) is brought to 10 V. The output voltage (red
trace) is clamped at 3.8 V. After some time the device enters thermal shutdown.

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NIS54xxGEVB

NIS5431 Reset from Thermal Shutdown

Continue with jumpers J2 (10 Ω), J1 (5431), J4, J8, and J13. Once the eFuse reaches thermal shutdown the
enable pin will fall to 1.4 V. Return the power supply to 3.3 V and press the blue button to reset the eFuse. An
auto-retry eFuse (MT2 part number suffix) does not latch and automatically cycles the enable pin. For auto-retry

eFuses the demo board’s green and yellow indicator enable pin indicator LEDs will flash as the enable pin cycles

between states.

Figure 5: This test shows how the enable pin is used to reset the device after a thermal shutdown
event. After pressing the blue button the enable pin falls to 0 V and then comes to about 3.3 V
after releasing the blue button. At that point the eFuse turns on. An auto-retry device will reset
automatically from thermal shutdown and pressing the blue button is not necessary.

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NIS54xxGEVB

NIS5431 Overcurrent Protection

Continue with jumpers J2 (10 Ω), J1 (5431), J4, J8, and J13. With VCC set to 3.3 V, press the large green
button to short circuit the output. A power supply capable of supplying more than 3 A is recommended. The
mechanical switch will bounce, but the eFuse will have no issue responding to this disturbance. It will respond to
the fault within 10 μs and the current will be limited to the short circuit current limit level. After some time the
device will enter thermal shutdown due to the high current and voltage between VCC and source (output voltage)
pins. An auto-retry eFuse (MT2 part number suffix) does not latch and automatically cycles the enable pin. For
auto-retry eFuses the demo board’s green and yellow indicator enable pin indicator LEDs will flash as the enable pin
cycles between states.

Figure 6: This is a demonstration of the current limiting circuit. The eFuse responds quickly to
the short circuit event and begins conducting at the short circuit current limit.

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